1. Field of the Invention:
The invention resides in the field of membrane processing devices for fluids and more particularly relates to the mechanical structure of cells used for those processes.
2. Description of the Prior Art:
Cells comprised of comparatively thin flat plates having a large central aperture and fluid distribution ports with passages leading to or by-passing the central aperture are well known in the prior art. In particular, electrodialysis stacks make extensive use of this concept. However, in prior art structures each plate or frame is of a configuration specific to the flow requirements of the cell in which it is to be used. Such frames are usually rectangular in shape and are arranged to combine with other similar frames, membranes, and electrodes to form a complete cell. In the prior art such adjacent frames are not rotationally symmetric and not interchangeable after partial rotation. A plurality of cells are stacked to form an entire processing assembly the size and number of such cell determined by the intended application of the unit.
As pointed out above, within a cell, the frames of these cells are not interchangeable with one another, each having its own unique arrangement of ports and recesses for fluid distribution, membrane containment, stack assembly and the like. Neither may such frames be positioned in any but the way in which they were designed to fit into the cell.
In contrast to the prior art, the device described herein comprises a universal cell plate analogous in function to the aforementioned frames but which may be used singly or in a stack arrangement for any of the fluid distribution and processing functions heretofore requiring specific structures each with unique configurations. As will be more fully explained, this is accomplished by arranging fluid distribution ports within the plate in a symmetrical configuration about a central aperture. Connecting passages extend from some but not all of the ports to the central aperture resulting in fluids being admitted from the ports to the area of the central aperture depending upon the orientation of the plate with respect to other plates in the stack and the input and output ports of the fluids to be processed.